Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of a first image in a sequence for a displayscreen or portion thereof with transitional graphical user interfaceshowing our new design;

FIG. 2 is a front view of a second image thereof; and,

FIG. 3 is a front view of a third image thereof.

The appearance of the transitional images sequentially transitionbetween the images shown in FIGS. 1 through 3. The subject matter ofthis patent includes a process or period in which an image changes intoanother image. This process or period forms no part of the claimeddesign.

The broken line showing of a display screen or portion thereof withtransitional graphical user interface is included for the purpose ofillustrating portions of the article and forms no part of the claimeddesign.

CLAIM The ornamental design for a display screen or portion thereof with transitional graphical user interface, as shown and described. 